Apparatus for making filters and the like



9% 1943. E. c. sLpAN ETAL 2,337,575

APPARATUS FOR MAKING FILTERS AND THE LIKE Original rm: July 15, 19 8 4 Sheets-Sheet. 1-

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E. C. SLOAN ETAL APPARATUS FOR MAKING" FILTERS AND THE LIKE Original Filed July 15. 1938 4 Sheets-Sheet 2 TORS. dwa/gob%fl%cuz/ INVEN I! Illllllll'IlllIl/llIl/ll"it"llllll'llll Dec. 28, 1943. E. .c. SLOAN ETAL.

APPARATUS FOR MAKING FILTERS AND THE LIKE Original Filed July 15, 1938 4 Sheets-Sheet 3 w zrlwacd I dffiernmv M; 1 ,{N y

1943- E. c. SLOAN ETAL 2,337,575

APEARA'I'US FOR, MAKING FILTERS AND THE LIKE Original Filed July 15, 1938 4 Sheets-Sheet 4 moon ono "Byway z I VIII/II Patented Dec. ltd

mmimii iii;

assists MFELRATUS WGR i3 ill E i.

Edward Q. Sloan and Au H. libel-man,

Geneva, lll., as aignors to Jesse B. Hawley,

Geneva, Bl.

. application July 15, 1938, San No. 219,454. Divided and application Novemher 17, 1941, Serial No- $19A3 on a median plane through the transferrer and This invention relates to apparatus for making filters adapted for filtering oil, liquids and other fluids, and which filters are made from accreted fibrous pulp.

This application is a division of our copending application Serial No. 219,454, filed July 15, 1938.

Our invention comprehends apparatus for making a filtering member that is economical to manufacture, simple in construction, of ample strength, efrlcient in operation, easy oi replace other fluids than oil, as well as for separating one 3 fliiuid from another; g

Our. invention" also includes apparatus for forming on the surface or the parts of a filter member, of valleys, furrows, grooves, ridges d 'showingthe wet carcass on the inner surface thereof after having been removed from the felting form and prior to its application upon the folder. r

Fig. 6 is a fragmentary longitudinal vertical section taken on a median plane through the f der of our invention and showing the carcass applied thereto by the transferrer, but omitting for conservation of space the lower portion of the folder and showing the folder in its extended position prior ,to the folding'operation.

Fig. 7 is a longitudinal vertical section of the .iolder including the lower portion omitted from Fig. 6, and showing the movable parts of the folder and the carcass in the position and condition occupied after the folding operation has been efiected and with the transferrer still in position around the folded carcass.

Fig. 8 is a view partly in side elevation and partly in section of the parts sh'bwn in Fig. 7, with the transferrer of Fig. 7 removed and a second transferrer in position over the folded carcass for 4 removing the same from the folder.

the like, either straight or irregular, such that the a rough or irregular surfaces will pet the passage in a general longitudinal direction of the oil or other fluid being filtered when said surfaces are indirect contact withother faces such as the interior wells of the filter casing, other of said surfaces, and the like, thus eliminating the noose sity of separate supporting members.

Our invention further includes apparatus for accreting a wet fibrous carcass onto a porous jormer, removing the carcass from the former,

and a folder for collapsing sections oi the carcass one within another.

Other objects, advantages and camhiiities inherently possessed by this invention will later become more readily apparent.

in the drawings: V

Figure l is a more or less diagrammatic vertical cross-section through the pulp bath tank and showing in general the apparatus for making our novel fibrous pulp oil filter members.

Fig. 2 is a side elevation of the wet accreted carcass before being folded into finished shape.

Fig. 3 is a perspective view of a filter member made in accordance with our invention.

EFig. i is,a longitudinal vertical section taken on a median plane of one of our felting forms and showing the wet fibrous carcass accreted thereon.

Fig. 5 is a longitudinal vertical section it tlii ' ing form only.

Fig. 9 is a vertical section taken on a median plane through the folded carcass and showing the drying turns in position therein and the carcass and drying forms in position upon the centering plate.

Fig. 10 is a plan view looking down upon the top of Fig. 9 either before or after drying.

Fig.1]. is a plan view looking down upon the centering plate. 4

Fig. 12 ran fragmentary view partly in section of the lower portion of the felting form.

Fig. 13 is a fragmentary plan view of Fig. 12.

- Fig. 14 is a horizontal transverse section taken on line i i-ii of Fig. 6 but through the folding form only.

Fig. 15 is a horizontal transverse section taken on the line 55-! ii of Fig. 6 but through the fold- Fig. 16 is a plan view looking down on the top of one of the drying forms in extended position.

Fig. 17 is a fragmentary plan view of the hinged portions of the drying form of Fig. 16 but showing the same in collapsed position.

Fig. 18 is a side elevation, partly in section and partly broken away of Fig. 17.

Fig. 19 is a fragmentary vertical longitudinal section through the folder, folded carcass and lower portion of the transferrer, and showing the drying forms in position therein prior to removal of the folded carcass from the folder.

ilhe formation of our improved filter members is accomplished in general by first accreting onto a suitable perforated form irom a bath of fibres a wet carcass of the desired thickness and elongated, but having a plurality of cylindrical portions, each succeeding cylindrical portion being greater in diameter than the preceding cylindrical portion and of such length that while still wet this carcass will be folded into collapsed form, with the cylindrical portions of different diaineters'concentric to each other but integraliy connected together. After the carcass is felted onto the felting form the latter is raised out or the bath and the carcass removed from the felting form by a transferrer, by which it is transferred to the folder and folded while wet into the shape referred to. While we have shown in the drawings the various cylindrical portions as being of cylindrical outer contour except for two that are longitudinally fluted, we wishit understood that these portions of different diameter may be of any suitable cross section other than cylindrical, such as square, oblong, elliptical, rectangular or, if desired, of irregular contour or'conical.

Referring more in detail to the drawings, it will be seen in Fig. 1 that in one embodiment of our invention we provide a felting form P which is formed of a plurality of tubular portions l, 2, 3, i and 5 of any suitable cross-sectional shape, and each tubular portion from I to 5, respectively, being of greater diameter than the one preceding the same. In other words, these tubular sections 2 to 5 each increase in diameter respective to the one preceding it from the free end of the felting form to the base 6. The base 6 of felting form F is securely fastened by bolts or other suitable means to a plate l angularly formed on the free end of the supporting arm 3, which latter is suitably pivoted at ii to the lug I0 fixed to one of t e side walls of the tank H, which tank contains a fibrous bath i2. This bath consists of the fibrous material being used immersed and thoroughly mixed in a suitable proportion of water.

A longitudinal cross-section through a felting form is shown in Fig. 4, in which the tubular portions i, 2, 3, 3 and 5, as well as the closed end it, are formed with a large number of open= ings ll, over which is placed a covering of wire mesh cloth it to prevent the pulp from. passing through said openings.

The felting form F is shown. in d with the wet carcass 2i! after being felted thereon and just before removal therefrom by the main transferrer 2-3. The base or lower portion of the wet carcass, as seen in Fig. i, is formed with the basal flange 22, which flange, as pointed out later herein, is used for clamping the filter element in position in the filter casing. The felting form, the transferrers and the folder of our iiivention may be made of brass, copper or other suitable material, preferably a material that will be rust resistant.

Referring again to Fig. 1, as soon as the felting form has been in the bath a sufficient length .of time to receive the desired thickness of fibre deposits thereon to form a carcass of suitable thickness, the felting form F with the accreted fibres thereon, is swung upwardly around folcrum 9 out of the bath and into the vertical position shown in solid lines. The position of the felting form in the bath is shown in dotted lines. As soon as the felting form F with carcass accreted thereon has reached the vertical position re erred to above, the main transferrer 23 (shown in detail in Fig. 5) is lowered thereover and an air suction created therein through the suction pipe Z i in order to hold the carcass 20 in gripping engagement with the transierrer and tend to release it from the felting form. This release from the felting form is further as" sisted by blowing air into the felting form through the air pipe 15, after which the main transerrer 23 is raised upwardly away from the felting form to remove the carcass from the latter and permit the felting form to again be swung downwardly into the bath to have formed thereon a carcass. The transferrer 23 may be raised and lowered by any suitable means, we, for illustrative purposes only, having shown in Fig. 1 a cable 25 passing over pulley 26 and secured at El to the transferrer 23. Any suitable power may be applied to the cable 25 to raise and lower the same as desired. We also wish it understood that any other suitable and adaptable form of means ior raising and lowering the transferrer may be used without departing from the spirit of our invention.

In tne foregoing it is to be understood that as soon as the fibres have been accumulated on the exterior of the felting form to the desired thickness, the suction through pipe l6 will be maintained until the felting form with its wet carcass thereon has moved out of the bath so as to prevent the deposited fibres from being washed away from the felting form. As soon as the felting form has moved out of the bath the suction through pipe M will be stopped, or if it is desired to remove more of the water from the carcass on the felting form the suction may be continued somewhat longer, but it is essential that before the transferrer 23 after being applied to the wet carcass is moved upwardly to remove the carcass from the felting form, the

- suction must have been out ed and, if desired,

some air pressure applied as referred to above.

The felting forms F may be arranged in batteries of any desired number in order to speed production. A corresponding battery of transferrers 23 with a transferrer for each felting form will likewise be provided for removal of the wet carcasses from the felting forms and to transfer them to the folders. After the felting form F (or battery of felting forms) has again been lowered into the bath the folder S is moved on its carriage 28 to the left as viewed in Fig. i, so as to come directly under its corresponding trans ferrer 23. If a plurality of transferrers and felting forms are used, a corresponding number of folders will likewise be used for obvious reasons. As soon as the folder S is directly under the transferrer 23, the latter will be lowered onto the folder and when the wet carcass is in place therein the suction through pipe 26 of the transferrer will be cut off and a desired amount of air pressure will be introduced into the interior of the transferrer through air pipe 2%, and at the same time suction will be applied to the interior of the folder through suction pipe 30. The transferrer 23 will then be raised to its elevated position in Fig. 1, the wet carcass at the same time remaining on the folder S to be folded as later herein described.

The main t .nsferrer '23, as shown in 5, comprises the c er shell 3! and the inner shell and the end wall 33, to form between the walls 39, 212 an air space 34, t which are connected suction pipe 2 1 and the air pipe 29, so that upon selective and individual manipulation of these pipes the space 36 within transferrer v to the folder.

23 may have applied thereto either a suction or air pressure as desired, the suction being to facilitate removal of the wet carcass from the felting form and the air pressure being to facilitate removal of the wet carcass from the transferrer The inner tubular wall 32 of the transferrer 23 is formed with a suitable number of openings 35, so that the suction or air pressure within chamber 34 will be effective upon the wet carcass in either removing it from the felting form by suction or placing it upon the folder by air pressure. The lower end of the transferrer 23 is suitably formed at 3,6 to fit over and press out smooth the basal flange 22 of the wet carcass and at 31 with an inset shoulder and depending portion to fit over and within the ring 38 on tne lower end of the felting form F, ring 38 serving as a guide for the lower end of the transferrer.

The folder S is shown in detail in Fig. 6, except that the lower portion of the same has been omitted for convenience, this lower portion, however, being shown in each of Figs. 7 and 8. In

describing this folder reference will be made to .low tubular section 44. Fixed to outer surface of the intermediate section 43 are the two spaced apart rings 45 and 46, the outer edges of which have a snug sliding fit with relation to the inner surface of the outer casing 39. These rings are spaced apart such distance that when the intermediate section 43 is extruded as far as it will go, the upper edge of ring 45 will contact the annular flange 41 fixed to the interior of the upper end of the outer casing 39, and when this contact takes place the upper edge of ring 46- will be just below the open irmer end of suction pipe 36 as seen in Fig. 6.

When ring 45 contacts flange 4'l the upper end portion of the intermediate section 43 will have protruded above the top of the outer casing 39 a distance equal to the length of the tubular stepped portions 3 and 4 of the felting form F. At the same time under the air pressure introduced through air pipe 4|, the inner section 44 of the folder will have been extruded until the upper edge of ring 48 will have contacted the lower edge of annular flange 49 formed on the I interior of the upper end of the intermediate section 43, and the inner section 44 has protruded a distance equa1 to the length of the tubular portions and 2 of the felting form. Ring 48 is fixed to the exterior of the inner section 44 and has a snug sliding fit with the interior of themtermediate section 43. Also fixed to the bottom end of the middle section 44 is a circular end plate 50, the outer edges of which have a snug sliding fit with the inner walls of the intermediate section 43. Securely fixed to end plate 50 by means of suitable nuts and threads on each side of plate 50, is the rod which at its lower end is fixed to the piston 52 by a. nut threaded to rod 5| on each side thereof. It will thus be seen that the two elements 56 and 52 are rigidly connected together for simultaneous endwise movement and serve as two piston heads slidably mounted upon the interior of the intermediate member 43.

The lower end of the intermediate tubular member 43 has fixed thereto an annular plate member 53, the outer edge of which has a snug sliding fit with relation to the inner walls of the outer casing 39. Plate 53 has an opening 54 in its central portion to receive the lower nut on rod 5|. and also permit the passage of air therethrough to move piston head 52 upwardly when air pressure is introduced through pipe M, and to move the same downwardly when suction is applied through pipe 42. Assuming the parts in the position shown in Fig. 7, the application of air pressure through pipe 4| will force piston head52 with the inner member 44 and the plate 53 with the intermediate member 43 upwardly to extrude said inner and intermediate portions until rings 48 and 45, respectively, hit flanges 49 and 41, which will bring the parts into position shown in Fig. 6, and which position these parts occupy when the main transferrer 23 is introduced over the folder S to app the wet carcass thereto as shown in Fig. 1.

- In order to permit a desired amount of suction to be applied to the interior of the folder when the main transferrer 23 is applying the wet carcass thereto, suction is applied through the suction pipe 30 which, as noted in Fig. 6, is above the ring 46 and piston head 52, thus enabling this suction to be applied to the offset tubular sections corresponding to sections 2, 3, 4 and 5, simultaneously with the application of the air pressure below plate 53 and piston head 52 to prevent the collapsing or lowering of the inner section 44 and the intermediate section 43 while receiving the wet carcass. To permit this suction through pipe 30 to be applied throughout the entire length in fully extended position from ring 46 to the upper end of inner section 44, the various parts are provided with a suitable number of openings through which the suction will to a sufflcient degree act upon a wet carcass to hold it to the folder when transferred thereto from the transferrer 23.

While any suitable number of holes may be used as desired, we have found it very satisfactory to provide approximately twelve V8 inch diameter holes 55 through the walls of the upper smallest section of the inner section 44; approximately four 4 inch diameter holes 56 in each of the valleys of the fluted portion A; approximately twelve A inch diameter holes 51 in that portion of the lower end of inner section 44 falling below ring 48; approximately twelve /8 inch diameter holes. 53 in that portion of the in: termediate section 43 falling immediately opposite that portion of the inner section below ring 49 when extended; approximately four,% inch diameter holes 59 in each of the valleys of the fluted 'portionB; approximately twelve inch diameter holes '60 in that portion of the intermediate section 43 lying between rings 45 and 46; and approximately eighteen inch diameter holes 6| in that portion of the outer shell 39 lying between flange 41 and ring 46 when the folder is extended. It is, of course, understood that these sizes and number of holes are only approximate and may be changed in number and dimension as desired within the limits of successful operation.

The fluted portions referred to are shown in cross-sectional detail in Figs. 14 and 15. Fig. 14 being a section on the line l4, l4 of Fig. 6 and Fig. 15 being a section on the line |5, |5 of Fig. 6. The fluted section of which a cross-section is shown in Fig. 14, is designated generally as A, and the fluted section of which a cross-section is shown in Fig. is designated generally as B. These fluted sections are formed in the exterior face of the metal of the larger portion of the inner section it and the larger portion of the intermediate section Q3, respectively, as indicated in Fig. 6, and are provided to assist in the stripping action When folding the wet carcass in the folder, to-wit, the stripping of the wet carcass from the adjacent faces of the folder during the folding action, which folding action will be better understood from an inspection of Figs. 6 and 19, Fig. 6 showing the wet carcass and associated parts of the folder before the folding operation begins, and Fig. 19 showing the folder and associated parts upon completion of the folding movement. Fig. 6 and Fig. 19 show the transferrer 23 as being still in positionboth before and after the folding operation, but this transferrer may, if desired, be removed and the folding operation take place after removal of this transferrer. This is a matter of choice and can be operated either way as desired.

Referring to Fig. 14, the fluted section A is provided with any suitable number of flutes or valleys 62, eight being shown in the drawings for illustrative purposes only, and this fluted section is covered with a thin perforated metal covering 63 or other suitable open-work material, preferably having a large number of small openings therein, it being remembered, as pointed out above, that openings are provided from the bottom of each of the valleys or fluted portions 52 to the interior of the inner telescoping section it. The flutedsection B being of a larger diameter will have a larger number of flutes or valleys, these numbering, as shown in Fig. 15, sixteen, this fluted section otherwise being formed and covered with perforated thin metal as described in connection with fluted section A in Fig. 14.

Due to the more or less fragile or crushable nature of the wet carcass after being folded, we prefer to provide perforated drying forms, which are shown in Figs. '7, 9, 16, 1'7, 18 and 19. Drying forms 66, 65 and 66, as seen in Fig. 9, are provided respectively for the inner, inter= tion through suction pipe 82.

mediate and outer concentric sections of ,the'

folded filter member. The construction of these drying forms is shown in detail in Figs. 16, 17am 18 as comprising the cylindrical side wall-of open mesh metal all having at its top the-in turned flange m, the vertical edges iii: and 69 of the side wall having fixed thereto the angular portions ill and ii, respectively, which angular portions carry the extending fulcrum pins '62 and i3, which in turn are fulcrumed to the plates or hinge members Hi and 15, which in turn are hinged together by means of the hinge pins iii. This hinged construction in effect forms a toggle and extends from the bottom to the top of these drying forms so that when the folded filter member is dried they may be easily emoved therefrom by swinging hinge members '55 inwardly from the position shown in Fig. 16 to the position shown in Fig. 17, which will decrease the diameter of these forms and permit them to be an outer face corresponding in inc-linationto the adjacent bottom edge of the wet carcass forming the supporting flange for the filter member. This bottom flange is secured by a pair of spaced screws, bolts or the like 0 to the bottom edge of the wall 6'! of the drying form opposite the toggle hinges but free throughout the rest of its circumference to permit the drying form to move inwardly therefrom when being collapsed. The drying forms for the intermediate and inner portions of the wet folded carcass may have their lower edges-straight as shown in Fig. 19, or slightly; curved, if desired, as shown in Figs. 6, '7 arid-9;

These drying forms are applied to those portions of thefolder corresponding to sections I, 3 and 5 of'the felting form shown in Fig. l by slipping them ilongitudinally thereover. These drying forms thus applied are shown at (it, and 66, respectively, in Fig. 6, before the wet carcass has been folded, and in Figs. 7, 9 and 19 after the wet carcass has been folded, and before the wet carcass has been removed from the collapsed folder in Figs. '7 and 19, and after such remoYal-in Fig. 9. The wet carcass is preferably removed from the collapsed folder by a second transferrer ll, which has a hollow space 18 between its outer wall iii and its perforated inner wall 80, to which hollow space air pressure may be introduced through air pipe iii or suc- The transferrer ii is of a shape and size to fit more or less closely over the exterior of the folded wet carcass after removal of the first transferrer 23, which latter, as stated above, may be removed either before or after the folding operation as desired.

In removing the folded wet carcass from the folder, suction through pipe 82 will be applied to the inner space '58 of transferrer ll, so as to make the exterior of the carcass adhere thereto, after which the carcass and transferrer will be lifted vertically upward to move the folded carcass and the drying forms together away from the folder, after which the wet carcass in the transferrer ll will be lowered onto a centering plate 83, which, as shown in Fig. 11, is of spider formation having the exterior ring portion ti l,"

which on its outer edge is outwardly and downwardly beveled as shown in Fig. 9, and whichis provided with the radial arms 85, three or more.

in number as desired, which arms have the upstanding lugs 85, which are tapered on their outer faces to receive the correspondinglytapered lower ends of the drying forms. Thesecentering plates insure that the several concentric cylinders of the filter member will be held properly in position and not permitted to become collapsed or distorted before drying. In the center of this centering plate may be provided an opening 8?, if desired, to more freely permit heated air to enter theinterior of the middle section of the folded filter member, air also freely passing upwardly into the interior of the intermediate and outer sections between'the' spider arms 85. These centering plates are provided with legs 3350 that they will stand up away from the carriage, table or other surface on which they may be resting during drying to permit free entry of air to the interior of the alter member while drying. If desired, these wet carcasses may be placed on an endless belt and have a continuous movement through the heated drying compartment.

The various steps in our improved method of forming our improved filter member will be readily understoodgfrornitheforegoing, and will .be seen in .generalgto 1 Consist-:01: nrstlqdepo iting,

by suctiononto am -elongated J felting; form a wet carcass of accreted,'interlaced and integrated fibres, having sections of steppedand-varying diameter, .and then moving such ,felting :forrns andxwet carcass out of the bath to an upright I position, and then applying over th wet 1, carcass on the, felting form v afirst transferrer, lifting the wet carcassfromthe felting aforul bY-Suchitranserrer with the application OfiSllCiiiOlfl 01513385- sure as desiredtransferringthewet carcasstoan extended folderandapplying :it thereto'..aud over which folder at certain sections 1 have been applied open-mesh drying forms, then -,collapsing the folder to fold the .wet carcassiinto a plurality of integrally united. concentric cylinders .or rather tubular forms, removing, the first transferrer either before or after the folding operation, ap-

plying asecond transferrer after. the folding operation to the exterior-of the folded-wet car-- case, then removing the second transfer-rer ,and

the wet carcass and dryingforms from thefolder and transferring them to .centering-platesand then placing said centering plates in drying chambers and drying the same to. produce fibrous filter members having a plurality ofconcentric porous'tubular portions for filtering liquids, and

a flange whereby such filter may be readily clamped in position and inpa filter casing, and

after its usefulnesshas expired :be readily removed therefrom and replaced by a new filter.

The flange for clamping the filter-member be tween suitabl clamping portions in a filter case ingis shown at 22 in Figs. 2, 3', 8,91and 1 9. As seen in Figs. 2, 3, 6, 7 and 19, inner section not the wet carcassretains its original form andshape, and during the folding, operation which, as is understood, is accomplished while the car-- cass is still wet, the felt-ling. occurs throughout the folding section s b and disc that in effect both of sect ons 17 and d are turned inside out so that'f section b lies concentric with and outside of section a, section 0 lies'concentric with and outside of section b, section 11 lies outsideof and concentric with section'c, and'sectione, formingthe exterior of the filter member, lies concentric d. see pa cular y" with and outside of section Figs. 2 and 3.

' 'I'he extending of the partsof the foldermay be accomplished, as stated earlieriherein. by introducing air through air pipe, which will force plate 53 with" itsattached intermediate section 43 and piston headiliz and; its attachedinnersection upwardlyuntil-rings liand 48' strike flanges 41 and .49, respectively. By Per-v i I 5 sections. of diflerent diameter of the folder is madepossible because of the inter-communicatingopenings between the various parts, as clearly seen ;-in Fig. 6. For illustration, any suitable number of openings I00 will be formed in ring ill 'alsoopenings "ii in ring '45, and openings I02 in end plate 50. V

The -folder may becollapsed also when the main transferrer is still in place by introducing airpressure through pipe 29 into the'space 34 within the transferrer to hold the wet carcass withmorepr less pressure against the folder andzto force the telescoping parts into collapsed position; {At the same time air is allowed to n-escape through suction pipe 30 and suction pipe modification and change without departing from the spirit ,of our invention.

Havingfnow described our invention, we claim:

1. A folder for an accretedhollow pulp carcass comprising a plurality of hollow sections telescopicallyv slidable one within another and having differentdiameters, said sections each formed with openingsthrough its walls, means for lim- Itingthe amount of extension of said sections, means for applying pressure within said sections to move them to extended position, and means for moving said sections to collapsed position.

2. A folder for an accreted hollow pulp carcass comprising a plurality of hollowsections telescopically slidable one within another and havmitting the continuance of a certain amount of- 7 air pressure through :air pipe ll; these parts will be held in extended position even while a; greater or less suction is being applledithroughsuction pipe 30 to,v assist in holding-thewet carcass to the folder and freeing it from the interior cfthe first transferrer. To effect collapsing; of the folder during the folding (dictation itris, only; necessary to stop the air pressure through pipe 4| and either utilize the. weight of the telescoping parts or apply any desired" amount of'suction through pipe 42, tojmove thetelescopingparts;

inwardly from the positionshown in Fig; 6: t0.

the position shown. in Fig. '7; a slight amount of suction being maintained on. suction pipe, 3ll or not as desired during this folding, operation. We

have, however, found itipreferablel to maintain a slight amount of suction on pipe 3.0 during folding. The'suction frompipe Slito theivariousl being telescopically retractable into nested coning difierent diameters, said sections each formed with openings through its walls, means for limiting the. amount of extension of said sections,

means for applying pressure withinsaid sections to move them to extended position, means for moving said sections to collapsed position and openJ-work drying forms removably positioned on the exterior of. certain of said sections.

3. A folder for folding filter members comprising aplurality of hollow sections telescopically slidable with relation to each other, said sections when extended having stepped portions. of differentldiameters adapted to receive a wet fibrous pulp filter membercarcass of internal contour similar to that of the external contour of the folder, the walls of said sections'havi'ng openings therein through which suction or pressure may be ;applied to the inner walls of the carcass,

'means for forcing said sections to extended position, and. means for enabling the sections and carcass thereon to be collapsed, during which collapsing movement those portions of the wet carcass on alternate sections will be progressively turned inside out so that when the folder is completely collapsed the carcass will be shortened from its original elongated form to short form, with a plurality of integral tubular filter portions positioned one within the other to provide a filtering surface of large area.

4. Apparatus for forming a filter member from an accreted hollow fibrous pulp carcass, comprising a folder having a plurality of hollow sections having different diameters and telescopicallyslidable one within another, said sections when protruded to their extended position receiving the fibrous pulp carcass, said sections centric, position and while being retracted foldingportions of the carcass inside out whereby is formed a folded accreted fibrous pulp filter having concentric integral sections increasing in diameter from the inside section to the outside.

5. Apparatus for forming a. filter member from an accreted hollow fibrous pulp carcass, comprising a folder having a plurality of hollow sections having different diameters and telescopically slidable one within another, said sections when protruded to their extended position receivingthe fibrous pulp carcass, said sections being telescopically retractableinto nested concentric position and while being retracted folding portions of the carcass inside out whereby is formed a folded accreted'flbrous pulp filter having concentric integral sections increasing in diameter sition and while being retracted folding portions;

of the carcass inside out whereby is formed a folded accreted fibrous pulp filter having concentric integral sections increasing in diameter from the inside section to the outside, means for limiting the amount of extension of said first mentioned sections, means for stopping the retracting movement when said first mentioned H sections are fully nested, and means for causing the first mentioned sections to move outwardly into extended position.

7. Apparatus for folding a hollow porous accreted fibrous pulp article, comprising a folder having a plurality of hollow sections of'difl'erent diameters and telescopically slidable one within another, said sections when extended receiving the hollow unfolded article and when collapsed one within another having positioned thereon the folded article, whereby during'the inward movement of the sections from extended to collapsed position the walls of the article will be folded to form a porous article with concentric integral sections of increasing diameter and folded one within another.

8. Apparatus for folding a hollow porous accreted fibrous pulp article, comprising a folder having a plurality of hollow sections ofdifi'e'rent diameters and telescopically slidable one within another, said sections when extended receiving the hollow unfolded article and when collapsed one within another having positioned thereon the folded article, whereby during the inward movecreted fibrous pulp carcass, comprising a folder having a, plurality of hollow sections of difierent diameters and telescopically slidable one within another, some of said sections being fluted on the exterior face.

g 10. Apparatus for folding a hollow porous accreted fibrous pulp carcass, comprising a'folder havinga plurality of hollow sections of different diameters and telescopically slidable one within another, some of said sections being fluted on the exterior face, some of said sections having stops to limit the amount of extrusion of the sections.

11. Apparatus for folding a hollow porous accreted fibrous pulp carcass, comprising a folder having aplurality of hollow sections of different diameters and telescopically slidable one within another, some of said sections being fluted on the exterior face the flutes on the fluted sections extending longitudinally of the section to facilitate the folding operation.

. 12. A folding apparatus comprising a member having telescopic sections over which an article to be folded will fit when the sections are extended, the sections being longitudinally slidable with relation to each other to fold the article longitudinally into sections one within another, the

sections of the folded article being integrally connected end to end and increasing in size from the inside folded section to the outside one.

13. A folding apparatus comprising a plurality of sections telescopically slidable one within an- 1 other, means for limiting the extent to which the sections may be inwardly-collapsed, the sections when extended'being adapted to receivev an article to be folded and when collapsed to fold portions of the article inside out and form a folded integral article having tubular sections enclosed one within-another and increasing in' cross-dimension from the inside to the outside.

14.- An apparatus for folding a fibrous article,

' comprising a plurality of hollow, perforated sections telescopicallyslidable one within another and over which an article to be folded will fit when the sections are extended, the sections when moving from'extended to collapsed postion folding the article longitudinally into sections one within another integrally connected end to end and increasing in size from the inside folded section to the outside one, means for limiting the amount the folding apparatus may be extended,

means for limiting the, amount the folding apparatus may be collapsed, andmeans for applying suction to the interior of the folding apparams to cause the article to have a tendency to adhere to. the folding apparatus sections during the folding operation.

15; A folding apparatus comprising a tele- .scopic member over which an article to be folded 6i)v will fit when the member is, extended, the telescopic member comprising a plurality of hollow sections longitudinally slidable one within another and movable from extended to collapsed poment of the sections from extended to collapsed position the walls of the article will be folded to form a porous article'with concentric'integralsections of increasing diameterand folded one within another, certain of the folder sections being formed on the exterior face with fluted sections to facilitate the foldingofthe article.

telescopic member during folding movement havturning the adjacent portions of 9. Apparatus for folding a hollow porous ac ing means for sition to fold the article longitudinally into shortened length, certain of the sections of the the article inside out,

EDWARD c. sLeAN. 'auqusrus 

